1. Field of the Invention
The present invention relates to a seat framework for use in a bus seat, and in particular to an structurally improved seat framework for use in a bus.
2. Description of Prior Art
In general, a whole of seat framework for use in a bus is formed by welding together some separate tubular frame members. Typically, as shown in FIG. 5, such bus seat framework is basically comprised of: a tubular seat back frame member (1); a tubular seat cushion frame member (2); a pair of first and second connecting tubular members (5A) (5B), each being of generally xe2x80x9cLxe2x80x9d shape; and a tubular support leg member (3).
As shown, the tubular seat back frame member (1) and tubular seat cushion frame member (2) are each formed by bending a tubular material into a generally xe2x80x9cUxe2x80x9d shape. Also, the tubular support leg member (3) is formed by bending a tubular material into a generally xe2x80x9cinverted Uxe2x80x9d shape. The two lateral frame portions (11) (11) of the seat back frame member (1) are connected and welded to the respective upper two ends of the first and second tubular connecting members (5A) (5B), whereas, likewise, the two lateral frame portions (21A) (21A) of the seat cushion frame member (2) are connected and welded to the respective lower two ends of the first and second tubular connecting members (5A) (5B). Another separate tubular member (22) is firmly connected between those two connecting tubular members (5) by welding, so that the seat cushion frame member (2) has a forward tubular cross frame portion (21) and a backward tubular cross frame portion (22).
The inverted-U-shaped tubular support leg member (3) is fixedly welded at its two vertical leg portions (31) (31) to a floor (F) of bus at a point near to an aisle floor (F1).
Designations (6) (6) denote a pair of angle pieces each having an xe2x80x9cLxe2x80x9d shaped cross-section. As shown, each angle piece (6) is fixed to each vertical frame portion (11) of the seat back frame member (1) as well as to each vertical portion of the connecting tubular member (5), thereby preventing deformation of both two vertical frame portions (11) when a front-side great load (FL) is applied from the forward side of seat framework in a direction backwardly of bus.
One of the two lateral frame portions (21A) of the seat cushion frame member (2) and the corresponding horizontal potion of the connecting tubular member (5) that is fixed thereto are welded on the upper surface (90A) of a support member (90) provided at a window side of bus (not shown). On the other hand, the forward and backward tubular cross frame portions (21) (22) of seat cushion frame member (2) are welded on the upper horizontal portion (32) of the support leg member (3).
In this conventional bus seat framework, a support bracket (7) is welded to the corner portion (52) of the first tubular connecting member (5A) and fastened on the upper surface (90A) of support member (90). Further, a rectangular reinforcement member (8) having a rectangular cross-section is firmly connected, by welding, between the corner portion (52) of the second tubular connecting member (5B) and the corner portion (32U) of the leg member (3). Such structure is designed to withstand a back-side great load (BL) applied from the back side of seat framework in a direction forwardly of bus so as to prevent deformation of the seat cushion frame member (2) and separation of the same from the support member (90) and leg member (3) when that load (BL) is applied to the seat framework.
However, the above-described conventional bus seat framework has been found defective in requiring a number of separate reinforcing elements, such as the bracket (7) and rectangular reinforcement member (8), which means that the assembly of the seat framework is time-consuming and troublesome.
In view of the above-stated drawbacks, it is a primary purpose of the present invention to provide an improved seat framework for bus which is of simplified structure which does not require a number of separate parts and elements.
In order to achieve such purpose, in accordance with the present invention, there is provided a seat framework in combination with a bus having a floor therein, which basically comprises:
a tubular seat back frame member of a generally inverted-U-shaped configuration including a horizontal frame portion and a pair of vertical lateral frame portions extending vertically from the horizontal frame portion, the tubular seat back frame member extending in a direction transversely of the bus, thus having a forward plane facing to a side forwardly of the bus and a backward plane facing to a side backwardly of the bus;
a tubular seat cushion frame member including: a forward cross frame portion facing to the side forwardly of the bus; a pair of horizontal lateral frame portions extending horizontally from the forward cross frame portion; and a backward cross frame portion facing to the side backwardly of the bus;
the pair of vertical lateral frame portions of the tubular seat back frame member being firmly connected with the pair of horizontal lateral frame portions of the tubular seat cushion frame member, respectively;
whereupon the seat framework has a forward side facing to the side forwardly of the bus and a backward side facing to the side facing to the side backwardly of the bus,
a support leg means for supporting the seat cushion frame member thereupon, the support leg means being fixed on the floor of bus; and
a reinforcing means fixedly provided between the tubular seat back frame member and the support leg means, wherein the reinforcing means is basically formed from a tubular material in such a manner as to reinforce the tubular seat back frame member and the tubular seat cushion frame member against deformation due to one great load applied toward the forward side of seat framework and due to another great load applied toward the backward side of seat framework.
In one aspect of the present invention, the reinforcing means may include: an angle portion of xe2x80x9cLxe2x80x9d shape in cross-section which is formed by subjecting one end portion of the tubular material to press working; and a tubular portion defined at another end portion of the tubular material. The angle portion may be fixed on and along either of said pair of vertical lateral frame portions of said tubular seat back frame, while the tubular portion be fixedly connected with the support leg means.
In another aspect of the present invention, the reinforcing means may include: a first angle portion of xe2x80x9cLxe2x80x9d shape in cross-section which is formed by subjecting one end portion of the tubular material to press working; a second angle portion of xe2x80x9cLxe2x80x9d shape in cross-section which is formed by subjecting another end portion of the tubular material to press working; and an intermediate curved tubular portion defined between the first and second angle portions. The first angle portion may be fixed on and along either of said pair of vertical lateral frame portions of said tubular seat back frame member, while said second angle portion be fixedly connected with said support leg means.
Other various features and advantages will become apparent from reading of the descriptions hereinafter, with reference to the annexed drawings.